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Cornell Dubilier BF-50 Capacitor Analyzer

In order to verify the vintage capacitor collection I slowly attained all perform to spec, I started to look for capacitor analyzers. The most well known is the Sprague TEL-OHMIKE series. Trying to find one of the Sprague designs at a reasonable price is difficult though. The TEL-OHMIKE brings $175-$250 on Ebay and I wasn’t trying to spend quite that much. I started to look at other well known capacitor brands and landed on Cornell Dubilier’s BF-50 model. I managed to find the BF-50 fully functional and shipped to my door for less than $75!



The BF-50 allows you to test for the following:

  • Open or Intermittent Capacitors
  • Shorted Capacitors
  • Leaky Capacitors
  • Capacitance Value
  • Grounded Capacitors

The BF-50 uses two transformers and two electron tubes. The 12A7 is the rectifier and the amplifier. The other is the 6E5 (“Magic Eye” ) which gives you the readings on the tests performed (listed above). The eye either opens/closes a specific amount or it will flash a specific amount per second to indicate the reading.

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Electrical Engineering student (Jr year) with a background in IT. Such as dealing with large scale network infrastructure upgrades at Lowe's HQ and former lead hardware tech for the NC Government.

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